施硅对白菜体内镉的分布及其吸收迁移的影响

在土壤外源镉污染下,施硅考察土培盆栽条件下白菜体内不同部位间镉的分布及其吸收迁移状况。试验表明,施硅显著降低白菜根、茎、叶中的镉含量和镉累积量,随土壤外源镉污染加剧,施硅抑制白菜各器官吸收累积镉的效果愈好,且不同硅水平处理间的差异亦渐趋显著。硅降低根的镉吸收系数,在土壤外源镉处理下,施硅降低镉的初级转移系数和次级转移系数以及地上部的镉转移系数,显著降低地上部的镉吸收系数;施硅增加白菜根、茎、叶中的硅含量和硅累积量,硅含量和硅累积量的分布为根>叶>茎和叶>茎>根,与镉含量和镉累积量的分布规律一致,白菜体内有可能形成硅-镉复合物以减轻镉的毒害。

Effect of Silicon on Cadmium Distribution and Its Uptake and Transport in Chinese Cabbage

Effect of silicon on cadmium distribution and its uptake and transport in different parts of Chinese cabbage were studied with pot experiment in exogenous cadmium contaminated soil by adding silicon. Results showed that the concentration and accumulation of cadmium in roots, stems and foliar of Chinese cabbage were dramatically lowered by adding silicon. With soil exogenous cadmium contamination deteriorated, the effect of silicon on inhibiting cadmium uptake strengthened and became gradually significant in different silicon treatments. Silicon reduced the root adsorption index of cadmium as well as primary transport index, secondary transport index, shoot transport index and shoot absorption index. Concentration and accumulation of silicon increased with its distribution in roots, foliar, stems and roots separately. Distribution of silicon as well as cadmium concentration and accumulation in different parts of Chinese cabbage was alike, which indicated that there may be silicon-cadmium compounds in plant tissues to alleviate cadmium toxicity.